Integrated Spectropolarimeter by Metasurface-Based Diffractive Optical Networks

TL;DR

This paper introduces a compact, integrated spectropolarimeter using metasurface-based diffractive optical networks, enabling simultaneous spectral and polarization measurements with high accuracy in a single shot.

Contribution

It presents a novel metasurface-enabled system that combines spectrometric and polarimetric sensing into a single, chip-integrated device with deep neural network decoding.

Findings

Accurate reconstruction of spectral and polarization information across broad wavelengths.

Successful demonstration of a chip-integrated sensor prototype with combined functionalities.

Validation of imaging capabilities and potential applications in biomedical and industrial fields.

Abstract

Conventional spectrometer and polarimeter systems rely on bulky optics, fundamentally limiting compact integration and hindering multi-dimensional optical sensing capabilities. Here, we propose a spectropolarimeter enabled by metasurface-based diffractive optical networks that simultaneously performs spectrometric and polarimetric measurements in a compact device. By leveraging the wavelength- and polarization-dependent phase modulation of metasurfaces, our system encodes the spectral and polarization information of incident light into spatially resolved intensity distributions, which are subsequently decoded by a trained deep neural network, enabling simultaneous high-accuracy reconstruction of both spectral compositions and Stokes parameters through a single-shot measurement. Experiments validate the proposed network's accurate reconstruction of the spectral and polarization information across a broad wavelength range, and further confirm its imaging capability. Notably, we demonstrate a chip-integrated sensor prototype combing both measurement functionalities into a commercial CMOS image sensor. This integrated platform provides a compact solution for on-chip multi-dimensional optical sensing, holding significant potential for versatile sensing, biomedical diagnosis, and industrial metrology.